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(Article compiled for the Kogelberg Branch of the BotSoc by Dr Allan Heydorn)

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Originating in south-eastern Australia, the Peppertree wattle, Acacia elata, is an invasive species causing increasing concern in the Western Cape. As with other invasive Acacia species, it displaces indigenous fynbos vegetation, lowers groundwater levels and poses a serious hazard during wildfires. It spreads rap idly through prolific seed production and dispersion. A. elata is listed under the National Environmental Management Biodiversity Act (NEMBA) as Category 1b. Its removal is therefore enforceable by law.

Unfortunately, A. elata is also spreading rapidly in Betty’s Bay. In some areas prolific stands of adult A. elata trees and their saplings occur in the immediate vicinity of the Kogelberg Biosphere Reserve (KBR). It therefore represents a serious threat to this internationally-recognised conservation area.

The smallish leaves of A. elata are very similar to those of the indigenous Keurboom (Virgilia oroboides) but can be distinguished by the pointed bipinnate leaves of the former versus the rounded tripinnate leaves of the latter. This characteristic enables accurate identification of even small saplings. Furthermore the flowers of the two species are notably different. Flowering seasons also differ with V. oroboides flowering from January to April while A. elata flowers on November and December.

The rapid growth and decorative leaves of A. elata make this species popular as an ornamental shrub. However, the shrubs grow to become trees of over 20m in height with massive trunks and root systems and, together with their dense clusters of saplings, they are exceedingly difficult to remove. The clusters of saplings become very dense and this characteristic drastically enhances the danger they represent during wildfires.

[Here's a link to further images of the tree.]

The Betty’s Bay Hack Group and especially hack convenor, Ed Silberbauer, have waged an unremitting battle for years to keep the spread of A. elata saplings at bay - especially in the immediate vicinity of the Disa Jeugkamp and its neighbouring properties on the border of the core zone of the KBR. During a hack that took place here in October 2014, it became clear once again that the removal of saplings is an impossible task as long as large numbers of mature trees remain standing. Earlier during the same month a wildfire driven by a powerful NW gale had destroyed several houses in Betty’s Bay. Had this fire been driven into the vicinity of the Disa Jeugkamp and set the dense clusters of A. elata saplings and mature trees alight, the entire camp as well as properties in its vicinity — including the Harold Porter National Botanical Garden — would have been placed at severe risk.

This catastrophic fire attracted the attention of the responsible authorities, especially the Bio-Security Directorate of the Department of Environment Affairs (DEA), who conducted an inspection of Betty’s Bay on 17 December 2014. Amongst others, they visited the Disa Jeugkamp and neighbouring properties. It was encouraging that one owner had already removed the bulk of A. elata from his property at substantial cost. Following the inspection, Mr Pagel Haefele, of the Disa Jeugkamp, drew up a plan for the systematic removal of A. elata from the camp terrain for submission to the DEA.